Disposable digital tourniquets and related methods of providing occlusion pressures to a single digit during surgical procedures

ABSTRACT

A single-use disposable digital tourniquet includes a generally rigid support body comprising first and second spaced apart cuff channels sized and configured to receive a cuff therethrough.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 11/222,956, filed Sep. 9, 2005, which claims priority to U.S. Provisional Application Ser. No. 60/620,817, filed Oct. 21, 2004, the contents of which are hereby incorporated by reference as if recited in full herein.

FIELD OF THE INVENTION

This invention relates to digital tourniquets for use in medical procedures.

BACKGROUND OF THE INVENTION

Injuries to the middle and terminal (end) portions of the thumb and other hand digits are relatively commonplace, with the number of treatment procedures for these types of injuries believed to number in the thousands per day in the United States alone. Examples of such injuries include lacerations, abrasions, avulsions, crush injuries, fractures, burns, and even partial amputations. The types of physicians and surgeons treating these types of injuries can include primary care physicians, emergency medicine physicians, general surgeons, plastic surgeons, trauma surgeons and orthopedic surgeons in offices, hospital operating rooms, emergency rooms, and even urgent care clinics.

Conventionally, a patient is given an anesthetic that can include a digital or regional block and/or a local anesthetic with LIDOCAINE or MARCAINE®. The hand and fingers are prepped and draped. A sterile rubber band(s) or Penrose drain (which is a thin-walled rubber tube) is used to stop arterial blood flow to the affected digit. This is done by wrapping the rubber band or Penrose drain around the proximal volar (palm) surface of the digit and clamping with a hemostat. When the procedure is complete, the hemostat is unclamped and arterial blood flow is restored.

Unfortunately, both the rubber band and the Penrose drain have a tendency to roll up as they are stretched axially, which can apply increased pressure on the finger or thumb as the surface area over which the force is applied decreases (it may be described as being similar to a wire being wrapped about the finger or thumb). In addition, use of these types of tourniquets may be such that the external pressure applied to the finger or thumb is not well controlled and may be excessive or beyond the pressure required to stop arterial blood flow. Unfortunately, when excessive pressure is applied to a small region, tissue and/or nerve damage can occur, particularly during relatively lengthy procedures.

In addition, other factors are influencing hand surgery that question the suitability of conventional digital tourniquets. For example, the population is aging and older patients tend to have tissue with atherosclerotic arteries that may be able to withstand less external pressure compared to a younger patient's tissue. In addition, health care costs are rising and more surgeries are being done in an outpatient or office setting, which are less likely to have access to specialized (costly) equipment. This trend may result in more local and digital blocks being used to treat injuries to the digit, which will likely increase the use of digital tourniquets.

In view of the foregoing, there remains a need for digital tourniquets that can provide sufficient occlusion pressure in an easy-to-use and economic manner.

SUMMARY AND EMBODIMENTS OF THE INVENTION

Certain embodiments of the present invention provide single-use disposable digital tourniquets that include a generally rigid support body comprising first and second spaced apart cuff channels sized and configured to receive a cuff therethrough.

In some embodiments, the digital tourniquets can have a first (digit contacting) surface with a curvilinear profile. The first surface can include a generally medial support region (that may be at the most depressed portion of the first surface) disposed intermediate the first and second cuff channels.

The tourniquets may also include two spaced apart cuff channels and an anchoring member configured to hold a first end portion of a cuff in the support body first channel and a clamping member configured to hold a spaced apart portion of the cuff proximate the second channel. In operation, the anchoring and clamping members can cooperate with the support body to provide a cuff with a nearly closed figure (such as an open ended loop) at a desired tension over a digit held on the support body.

In particular embodiments, the tourniquets can include a deformable member configured to operatively communicate with the cuff. The deformable member may be configured to automatically yield or break when the cuff is tensioned above a target threshold amount to provide a tactile and/or audible alert to a clinician that a target occlusion pressure has been achieved.

Embodiments of the present invention provide single-use disposable manually operated digital tourniquets that a physician or surgeon can relatively easily operate (typically without requiring assistance).

Other embodiments are directed to digital tourniquets that include: a generally rigid support body comprising first and second spaced apart cuff channels, wherein the support body comprises a first surface that, in position, contacts a target digit; and a planar non-inflatable elastomeric cuff that is slidably insertable through the first and second channels of the support body so as to extend through the first channel away from the first surface and into the second channel to provide a cuff with a curvilinear portion that extends outward from the support body first surface.

The cuff can include opposing first and second end portions. The first end portion can include a rod channel extending thereacross and a rod held therein with opposing end portions of the rod extending beyond the bounds of the cuff.

In some embodiments, the cuff can comprise a planar elastomeric material that is sized and configured to maintain its width dimension and resist roll-up in an operative (stretched) configuration.

In some embodiments, the tourniquets can be selectively used by a clinician in either orientation selected by the clinician, i.e., allowing a clamping portion to be located proximate a thumb of a patient irrespective of the affected hand.

Other embodiments are directed to kits of digital tourniquets providing for a range of different occlusion pressures. The kits include: (a) a first digital tourniquet generally rigid support body having first and second cuff channel lengths sized to accommodate a cuff having a first width; and (b) a second digital tourniquet generally rigid support body having first and second cuff channel lengths sized to accommodate a cuff having a second width that is greater than the first digital tourniquet cuff first width.

In some embodiments, the kit can also include first and second generally planar elastomeric cuffs, one having a first cuff width configured for insertion into the first support body and the other having a second cuff width that is greater than the first cuff width and is configured for insertion into the second support body. The different support bodies and associated cuffs can be configured to provide increased reliability for different preferential occlusion pressures so that a clinician can select the appropriate body/cuff in situ at a point of surgery.

Other embodiments are directed to kits of non-inflatable cuffs that include a plurality of elongate non-inflatable cuffs of different widths, each cuff having an end portion with a channel configured to accept a rod thereacross.

The foregoing and other objects and aspects of the present invention are explained in detail in the specification set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an anatomical drawing of the hand with some of the skin and superficial fascia removed to expose the two neurovascular bundles, each having one artery and one nerve, and an exemplary digital tourniquet according to embodiments of the present invention.

FIG. 2A is an anatomical drawing of the hand also illustrating the two neurovascular bundles and the proper palmar digital arteries with an exemplary digital tourniquet in position according to embodiments of the present invention.

FIG. 2B is a cross-sectional view of an exemplary digital tourniquet in one position according to embodiments of the present invention.

FIG. 2C is a perspective view of an exemplary digital tourniquet about a proximal phalanx portion of a digit according to embodiments of the present invention.

FIG. 2D is a perspective view of the digital tourniquet about a proximal phalanx portion of a thumb according to embodiments of the present invention.

FIG. 3 is an end view of one embodiment of a digital tourniquet support body according to embodiments of the present invention.

FIG. 4 is a side perspective view of the support body shown in FIG. 3.

FIG. 5 is a top view of the support body shown in FIG. 4.

FIG. 6 is a side perspective view of the device shown in FIG. 3.

FIG. 7A is a cross-sectional view taken along line 7-7 in FIG. 6.

FIG. 7B is a cross-sectional view of a different embodiment of the support body having an integrally molded anchor portion according to alternate embodiments of the present invention.

FIG. 8 is a bottom view of the device shown in FIG. 5.

FIG. 9 is a cross-sectional view of the device shown in FIG. 8 taken along line 9-9 and illustrating a deformable projection according to embodiments of the present invention.

FIG. 10A is an enlarged partial section view of the device shown in FIG. 9, illustrating a configuration of a deformable projection according to embodiments of the present invention.

FIG. 10B is an enlarged partial section view of the device shown in FIG. 9, illustrating another configuration of a deformed projection according to embodiments of the present invention.

FIG. 10C is an enlarged partial section view of the device shown in FIG. 9 with a different projection configuration.

FIG. 10D is an enlarged partial section view of the device shown in FIG. 10C, illustrating the different projection in a deformed configuration according to embodiments of the present invention.

FIGS. 11A-11E are schematic illustrations showing a series of configurations that a cuff can have in a digital tourniquet during use according to embodiments of the present invention.

FIG. 12 is a schematic illustration of a set or kit of different tourniquets according to embodiments of the present invention.

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

The present invention will now be described more fully hereinafter with reference to the accompanying figures, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like numbers refer to like elements throughout. In the figures, certain layers, components or features may be exaggerated for clarity, and broken lines illustrate optional features or operations unless specified otherwise. In addition, the sequence of operations (or steps) is not limited to the order presented in the figures and/or claims unless specifically indicated otherwise. In the drawings, the thickness of lines, layers, features, components and/or regions may be exaggerated for clarity and broken lines illustrate optional features or operations, unless specified otherwise.

It will be understood that when a feature, such as a layer, region or substrate, is referred to as being “on” another feature or element, it can be directly on the other feature or element or intervening features and/or elements may also be present. In contrast, when an element is referred to as being “directly on another feature or element, there are no intervening elements present. It will also be understood that, when a feature or element is referred to as being “connected”, “attached” or “coupled” to another feature or element, it can be directly connected, attached or coupled to the other element or intervening elements may be present. In contrast, when a feature or element is referred to as being “directly connected”, “directly attached” or “directly coupled” to another element, there are no intervening elements present. Although described or shown with respect to one embodiment, the features so described or shown can apply to other embodiments.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. The word “cuff' means a flexible band and/or strip of material configured to apply pressure to a target region of a digit. The words “digital” or “digit” refers to an anatomical member, i.e., a hand digit describes a thumb and/or a finger, and a foot digit describes a toe. The term “polymer” includes copolymers and derivatives and/or combinations thereof. The members 20, 30 can comprise a generally rigid elastomeric material. The phrase “generally rigid” means that the body may flex somewhat but is structurally sufficiently rigid to maintain its shape during normal use when the other components are assembled thereto.

Referring to FIG. 1, a digital tourniquet 10 is shown on a hand digit 15. As shown in FIG. 1, a digit 15 includes two neurovascular bundles 16, and, as known to those of skill in the art, each bundle 16 includes one artery and one nerve that extends from the hand to the tip of the forger. As shown, the digital tourniquet 10 includes a support body 20 and a cuff 30 that cooperate to apply occlusion pressure to the digit 15 undergoing treatment. FIG. 2A illustrates the tourniquet 10 on a hand with a partial dissection of the palm to illustrate anatomical features. FIG. 2B illustrates a partial section view of the tourniquet 10 in an exemplary position with respect to a cross-section of a finger and illustrating a nerve, artery and vein (palmar digital).

FIG. 2B also illustrates that the support body 20 includes a digit contact surface 20 c and first and second spaced apart cuff channels 21, 22. The channels 21, 22 can be configured to extend generally orthogonal to a plane extending across the contact surface 20 c and/or with respect to the digit 15 being treated. In position in the support body 20, the cuff 30 is configured as a closed perimeter segment 30 s above the support body 20. That is, the closed perimeter segment 30 s extends above the digit contact surface 20 c and opposing cuff sides 30 ₁, 30 ₂ are configured to enter and extend through a respective one of the first and second channels 21, 22. The cuff 30 is pulled to tighten cuff segment 30 s and cause the segment 30 s to exert occlusion pressure against the digit 15.

In some embodiments, a first side of the cuff 30 ₁ is secured to the body 20, typically inside or proximate the first channel 21. The cuff 30 is then directed to travel above the contact surface 20 c and travel through the second channel 22. A length of the second side of the cuff 30 ₂ typically extends beyond the bounds of the support body 20 out of the second channel 22. In use, a clinician can pull the second side of the cuff 30 ₂ to tension the cuff and apply occlusion pressure to the digit 15.

FIGS. 2C and 2D illustrate that in some embodiments, the tourniquet 10 can be positioned about a proximal phalanx portion of a digit. FIG. 2C illustrate an exemplary position of the device 10 on a finger and FIG. 2D illustrates an exemplary position of the device on a thumb. It is contemplated that the device 10 can be used at a number of suitable locations on a digit including for surgery on either the dorsal or volar surface, although conventionally the device may be used dorsally over the proximal phalanx as shown, for example, in FIGS. 1, 2C and 2D.

FIGS. 3-7 illustrate one embodiment of a support body 20. As shown, the support body 20 has a curvilinear digit contact surface 20 c. The contact surface 20 c may have a shallow or low profile such that the digit is held substantially exposed and accessible (relatively unimpeded) to a clinician. The term “shallow” typically means that the profile has a depression that is less than about 5 mm (for most adult uses). Pediatric tourniquet support bodies 20 may have a profile with a shallower dimension, such as less than about 3 mm.

FIGS. 3 and 7 illustrate that the contact surface 20 c may be generally arcuate and correspond to a profile of a portion of a digit to allow the support body to more conformally fit against the target digit region in use. For example, the curvilinear contact surface 20 c can be configured so that a digital mid-line of the digit being treated resides beyond (typically above) the bounds of the support body 20 when resting thereon. The body 20 can include first and second sides, A, B, respectively. The first channel 21 can be disposed on the first side A and the second channel 22 can be disposed on the second side B. A medial segment 23 can extend between and separate the first and second channels 21, 22. FIG. 4 shows that the medial segment 23 can be generally closed partition or body portion that can generally extend at least a major portion (or even entire) the thickness or depth dimension “D” of the body 20. Typically, the medial segment 23 defines at least a portion of the digit contact surface 20 c as shown in FIG. 5. The first side A may provide an anchoring function and the second side B may provide a clamping function as will be discussed further below. However, the invention is not limited thereto as the locations of the components and/or functions may be interchanged for certain embodiments.

The width W (FIG. 4) of the support body 20 can be configured to generally correspond with a width of a digit being treated. In other embodiments, the width of the support body 20 may be lesser or greater than that of the digit being treated. The spacing of the channels 21, 22 can be configured relative to each other so that the cuff 30 when attached and/or assembled to the support body 20 is able to generate the desired cuff pressure/configuration. The channels 21, 22 can be aligned and extend generally parallel in the depth dimension D. The channels 21, 22 can be closely spaced in the width direction to allow the cuff segment 30 s to fowl an open loop turn 30 t (FIG. 11A) that defines the closed perimeter segment 30 s above the digit contact surface 20 c.

In particular embodiments, as shown in FIG. 3, the support body 20 can be generally square about the axial and sagital directions (L×W dimensions). The digit contact surface 20 c can be configured to define a concave surface that contacts the target surface of the digit, which generally conforms with the finger (i.e., the contact surface 20 c may conform dorsally, volarly, and/or otherwise with the target placement). This configuration allows the body 20 to rest on the top (dorsum) of the finger. Other mounting configurations and orientations of the support body 20 relative to the digit may also be used.

In some embodiments, as shown in FIG. 5, the centerlines of the channels 21, 22 are spaced apart in the width direction between about 1-20 mm, typically between about 2-12 mm, and more typically between about 2-8 mm. During use, at the location the cuff exits the first channel 21 and enters the second channel 22, the cuff 30 can rest against the outermost edge of the respective channel at the contact surface 20 c. That is, the cuff 30 exits the first channel 21 and travels laterally outward a distance to wrap about the digit then travels laterally inward and into the second channel 22. The spacing distance of the channels 21, 22 may vary depending on the target treatment digit and age and gender of the patient. Typically, the spacing of the channels 21, 22 is such that they reside less than the width of a digit being treated so that the cuff segment 30 s is able to wrap about a greater side area of the digit proximate the contact surface of the support body 20 c and is sized so as not to pinch the skin on the digit (on the dorsum of the finger) of the patient. In some embodiments, the width of the medial segment 23 at the contact surface 20 c may define the separation distance of the channels as shown in FIG. 5.

The length L (FIG. 4) of the support body 20 can be sized to be about the same, or more typically, a small amount larger than the length of the channels 21, 22 and/or width of the cuff 30. The support body 20 can be a generally rigid lightweight body. The support body 20 can be single-use disposable or sterilized for re-use. The cuff 30 is typically single-use disposable. In some embodiments, the support body 20 is a generally rigid elastomeric body. In some embodiments, the support body 20 is a molded polymer body.

In certain embodiments, the support body 20 can include an anchoring side and a tension adjusting side B. Typically, as shown in FIGS. 4, 7 and 8, the anchoring side is proximate and/or in the first channel 21 while the tension adjusting side is downstream of the second channel 22. In some embodiments, a first end portion of the cuff 32 (FIGS. 9 and 10) can be configured with a rod channel 32 c that is sized and configured to receive a rod 33 thereacross. The rod 33 engages the support body 20 and anchors the first end portion of the cuff 32 to the support body 20. As shown in FIG. 9, in some embodiments, the channel 21 can include spaced apart retaining shoulders 28, 29 that project a distance across the channel 21 and hold the first end portion of the cuff 32 via the rod 33 in position in the body 20 during use. The shoulder 29 and/or corresponding end portion of the rod 33 can be configured to inhibit sliding. For example, the shoulder 29 and/or rod end 33 can have an increased friction coating or layer, such as a flexible adherent. The other shoulder 28 and/or opposing end of the rod 33 may also include such a material. The rod and cuff 33, 30 can be slidably attached and/or removed from the support body 20 before and/or after use. The tourniquet 10 can be single-use disposable.

The second end portion of the cuff 34 extends beyond the bounds of the support body 20 and allows a clinician to easily access the cuff to pull the cuff to a desired tension at which time the cuff can be secured against the body 20. Typically, the cuff 30 is secured to the support body 20 using an integral clamping device 40. FIG. 4 illustrates the support body 20 without a clamping device. As shown in FIG. 7A, the clamping device 40 can be configured with a pivot 41. The clamping device 40 can be biased to pivot toward the support body medial segment 23 to apply a clamping force sufficient to hold the cuff at a desired tension and/or occlusion pressure. During use, a clinician can push a handle 40 h to pivot the clamping device 40 away from the support body 20. When a desired occlusion pressure is reached, a clinician can release the handle 40 h, allowing the clamping device 40 to return to its biased closed configuration to pinch the cuff 30 against the support body 20. The clamping device 40 can include a serrated or teeth forward edge portion 43 (FIGS. 7 and 8) that may provide additional friction or gripping force. The clamping device 40 can be configured to pivot in and out of a groove 44 formed in a surface of the medial segment 23. In the embodiment shown in FIG. 7A, a discrete hinge can extend through the clamp 40 and attach to the body 20. In other embodiments, the clamp 40 can be integrally molded to the body 20 in a manner that provides the desired pivoting function as shown in FIG. 7B. For example, the clamp 40 shown in FIG. 7B can be integrally molded to an outer side edge portion of the body 20 without requiring a separate mechanical hinge component. The integrally molded clamp 40 can be biased to a closed (or open position) to allow the clamp 40 to pivot relative to the body of the device 20 between an engaged and disengaged position thereby holding and releasing the cuff 30 during use as desired. The clamp 40 and clamp connection can comprise elastomeric material, and in particular embodiments can comprise a polymer with sufficient structural rigidity to provide the clamping function. Other tensioning, attachment and/or clamping mechanisms and configurations can be used to adjust and/or maintain the desired tension/force.

As shown in FIG. 9, in some embodiments, the support body 20 can include a gauge or feedback mechanism that provides a tactile and/or audible alert when a certain cuff tension is reached or exceeded and/or when a certain occlusion pressure provided by the cuff 30 is reached or exceeded. In operation, a clinician can pull the cuff 30 out of one side of the support body 20 to tighten the cuff 30 against the digit being treated. Generally stated, when a certain external circumferential compression pressure is reached (mmHg) for a given cuff and/or body size, a clinician holding the cuff or proximate the support body 20 is able to feel and/or hear a change that automatically confirms to the clinician that a certain cuff tension and/or cuff pressure has been reached, allowing the clinician to apply a reliable relatively consistent pressure between patients.

In the embodiment shown in FIGS. 9, 10A-10D, a deformable projection 50 can be positioned in the first channel 21 of the support body 20. The deformable projection 50 can be configured as a deformable projection arm 50 a that is spaced apart from the retaining shoulder 28 as shown in FIGS. 9, 10A and 10B. During operation, the projection arm 50 a yields (deforms and/or breaks) to allow the rod 33 to move (typically down) to rest against the retaining shoulder 28 when a certain tension force is exceeded. Thus, the term “deformable” means that the member is configured to deform (typically non-elastically deform) or break when a certain force is exceeded. FIG. 10A illustrates that the arm 50 a can break to release the rod 33 while FIG. 10B illustrates that the arm 50 a yields but remains intact.

FIG. 10C illustrates that the deformable projection 50′ can include two laterally spaced apart deformable projections 51, 52 that impede the movement of the rod 33 until a target tension is exceeded. As shown in FIG. 10D, when sufficient tension is placed on the first end portion of the cuff 32 the rod 33 pushes against the projections 51, 52 to laterally separate the projections 51, 52 a sufficient distance to allow the rod 33 to move down (or up depending on the orientation of the body 20) to the retaining shoulder 28. As before, the deformable projections 51, 52 can be integrally molded to the channel 21 or formed or added as a separate component(s).

The deformable projection 50, 50′ can be configured to yield or break at a desired occlusion pressure. That is, the deformable projection 50, 50′ can be engineered to yield or break at a calibrated tension or pressure. The deformation can be associated with a tactile feedback (the cuff movement) and/or audible snap that can alert a clinician that a sufficient occlusion pressure has been reached without requiring electronic sensors or peripheral gauges.

In some embodiments, the projection 50, 50′ can be integrally molded to the body 20. For example, the projection arm 50 a shown in FIG. 9 can be designed in a manner that allows the arm 50 to deform (yield or break) when a desired tension is reached. In other embodiments, the projection 50, 50′ can be assembled to the body 20 as a separate component. The projection arm 50 a can have a reduced size or scored neck region, comprise a brittle or non-elastic material, and/or have a tension-calibrated shape or other design feature that can allow the projection to yield at a known and/or calibrated tension level to have the projection 50 preferentially deform.

FIGS. 11A-11E illustrate a series of configurations that a cuff 30 and/or tourniquet body 20 may experience in operation according to certain embodiments of the present invention. In use, the tourniquet 10 can be configured with the cuff segment 30 s loosely extending above the digit contact surface as shown in FIGS. 11A and 11B and slipped over the digit of interest, typically positioned over the proximal phalanx dorsally. The cuff 30 is then tightened as shown in FIG. 11C to apply occlusion pressure to the digit.

Conventionally, when performing surgery, a clinician sits on the radial (thumb) side of an outstretched hand. Many surgeons are right-handed, and will hold the tourniquet body 20 with their left hand while pulling up on the second end portion of the rubber cuff 34 via the clamp side (shown as side B) with their right hand. During tightening, the clinician can focus on the support body 20 (typically the gauge side (shown as side A)) to be able to stop pulling when the deformable projection yields or breaks. The clinician may want the gauge side (side A) of the support body positioned closest to the thumb for either right or left hand surgery. As shown in FIGS. 11D and 11E, the support body 20 can be selectively oriented by a clinician to position either side A or side B closest to the thumb. The orientation allows for clinician preference so that the clamping/pulling side B (clamping device 40 and cuff side 34) can be easily accessed by the dominant hand to allow for left-handed or right-handed clinicians and/or use on different hands.

It is also noted that although the support body 20 will typically reside above the digit (facing down) with the second end cuff portion 34 extending generally upward and/or outward therefrom, the invention is not limited thereto. For example, the body 20 may be located on a lateral side or under the digit and the cuff 30 pulled sideways and/or downward, as long as the clinician can pull the cuff 30 to tighten the cuff pressure during use.

The cuff 30 can be a generally planar non-inflatable member. The cuff 30 can comprise an elastomeric (typically non-latex) material that is configured to inhibit lateral rolling when tensioned. Other cuff materials may be used as appropriate. For example, the cuffs can comprise synthetic or natural fabric with synthetic or natural fibers or combinations thereof. The cuff 30 can be relatively wide, typically greater than 5 mm, and typically between about 5-15 mm. In some embodiments, the cuff widths can be provided in a range of sizes between about 8-15 mm. The cuff 30 can also be configured to have limited axial stretch (in the length dimension). The cuff 30 may have a resting width and a functional width (when tensioned). The cuff 30 may comprise a flexible substantially inextensible material that is able to generally maintain the resting width when tensioned.

Typically, within practical limits, a larger cuff width is desired (without affecting access to the treatment area) to provide a lower (minimum) occlusion pressure. The minimum finger occlusion pressure is a function of the circumference of the finger and the patient's systolic blood pressure. See, e.g., New finger cuffs for use with digital tourniquets, McEwen et al., J. Hand Surg 1988: 13A: 888-892, the contents of which are incorporated by reference herein. It is believed that using the digital tourniquets 10 of the instant invention can reduce occlusive pressures below 50% of the maximum (uncontrolled pressures) that may be generated by either a Penrose drain, a rolled glove finger or rubber band.

FIG. 12 illustrates that the tourniquets 10 can be configured in a plurality of sizes with a corresponding adjustment in the channel sizes 21, 22 and cuff widths 30 to accommodate typical anatomical variations (digit circumference and/or systolic pressure) in the treatment population. Different breaking or yielding strengths of projection(s) 50, 50′ can be designed into the different sized bodies 20. Smaller circumference fingers (measured at the middle of the proximal phalanx) may have sufficient occlusion pressure at lower tensions. Alternatively, a plurality of different cuffs 30 of varying cuff widths can be pre-calibrated to be used with a single body 20. In any event, a plurality of different sized tourniquets 10 (bodies 20 and/or cuffs 30) can be provided as a kit to allow a clinician to easily select the optimal one for use in situ, based on one or more patient-specific parameters such as digit circumference. As such, each tourniquet 10 can be sterilized and packaged for single-disposable medical use. Each body 20 can be individually packaged with or without one or more cuffs in different cuff widths. Alternatively, each body can be individually packaged and a selection of cuffs 30 can be packaged together, as it is anticipated that the cuffs 30 will be cost-effective components, which even if packaged as two or three selectable cuffs for a particular tourniquet body 20, can be disposed of if not selected for use for that patient.

The cuffs 30 can be marked with identifying indicia, such as a digit size range and/or target occlusion pressure range when used with a particularly sized body, to reflect the tension and/or projected pressure that will occur using the selected cuff 30 in the body 20 (and potentially related to estimated finger circumference) if the cuff 30 is tensioned to the breaking/yielding point of the projection(s) 50, 50′. The cuff width can affect the applied occlusion pressure as larger cuff widths provide an increased area with reduced pressures for the same applied force P=(F/A). Further lower pressures can be successfully used for larger cuff widths.

Estimates of target pressures using different cuff widths are provided in Table 1. It will be understood that these values can vary based on design considerations, such as cuff thickness, cuff elasticity, cuff width and the finger circumference that a particularly sized tourniquet body/cuff will accommodate. The yielding and/or breaking tension of projection(s) 50, 50′ can be correlated to the desired occlusion pressure(s). In some embodiments, the breaking/yielding tension may be a maxima for the cuff and contemplated larger digit size and/or may be averaged for a range of patient sizes.

TABLE 1 PROJECTED CUFF WIDTH V. CONTEMPLATED PRESSURE Est. Target Occlusion Finger Pressures Cuff Width Circumference 225 mm Hg-350 mm Hg 10 mm 50-70 mm 275 mm Hg-375 mm Hg 15 mm 70-90 mm 300 mm Hg-350 mm Hg  8 mm 40-50 mm

The foregoing is illustrative of the present invention and is not to be construed as limiting thereof. Although a few exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all, such modifications are intended to be included within the scope of this invention as defined in the claims. In the claims, means-plus-function clauses, if used, are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Therefore, it is to be understood that the foregoing is illustrative of the present invention and is not to be construed as limited to the specific embodiments disclosed, and that modifications to the disclosed embodiments, as well as other embodiments, are intended to be included within the scope of the appended claims. The invention is defined by the following claims, with equivalents of the claims to be included therein. 

1. A single-use disposable medical digital tourniquet, comprising: a non-inflatable planar cuff having a length with opposing first and second end portions; a rod extending across one end portion of the planar cuff; and a block body sized and configured to hold a digit against a concave upper or lower surface thereof, the block body comprising first and second closely spaced apart cuff through channels sized and configured to receive the cuff therethrough, wherein the first channel comprises at least one blocking member extending laterally across at least a portion thereof, wherein the first channel further comprises a pair of laterally spaced apart first and second cuff retaining shoulders that face each other and reside proximate to but below or above the at least one blocking member, wherein, in use, the rod and corresponding end portion of the cuff are first held in the first channel by the at least one blocking member at a first position and/or orientation under the upper surface of the block body until a defined force associated with a safe occlusive pressure of between about 225 mm Hg and 375 mm Hg is exerted on arteries in opposing sides of a target digit, then the at least one blocking member yields, separates or breaks to allow the rod to automatically translate to a second position or orientation under the upper surface of the block body whereby the tourniquet mechanically generates an audible and/or tactile feedback to a user that a safe tourniquet pressure has been reached to thereby inhibit an unsafe occlusive pressure.
 2. The digit tourniquet of claim 1, wherein the at least one blocking member comprises a deformable projection arm that extends across a minor portion of one side of the first channel, and wherein the rod is held in the channel at an angle against the deformable projection arm and one of the first or second cuff retaining shoulders until the defined force is reached and the deformable projection arm yields to allow the one end portion of the rod to translate a further distance into the first channel to reside against the second cuff retaining shoulder.
 3. The digit tourniquet of claim 1, wherein the at least one blocking member comprises a pair of aligned spaced apart projections that cooperate to hold the rod at the first position in the first channel, then when the defined tension is reached, the rod pushes the spaced apart projects further apart to move down or up to reside against the retaining shoulders.
 4. The digit tourniquet of claim 1, wherein the block body is a single-piece molded block body which comprises a polymer material.
 5. The digit tourniquet of claim 1, further comprising a pivoting clamp attached to the block body with an outwardly extending lever arm that is configured to allow a user to pivot the clamp to close against an inner surface of the second channel to trap a portion of the cuff between the clamp and the inner surface of the second channel to hold the cuff at a desired tension and allow the user to pivot the clamp in a reverse direction to release the cuff.
 6. The digit tourniquet of claim 1, wherein longitudinally extending centerlines of the first and second channels reside between about 1-20 mm apart, and wherein the cuff has a width of between about 8-15 mm.
 7. The digit tourniquet of claim 1, wherein the concave surface comprises a shallow concave profile with a depth of less than about 5 mm, and wherein the concave surface has first and second apertures that align with first and second channels and a medial closed outer surface portion that resides between and separates the first and second cuff apertures.
 8. The digit tourniquet of claim 1, wherein the digit tourniquet is sterile for surgical use.
 9. A digit tourniquet comprising: a substantially rigid block support body comprising first and second spaced apart cuff channels that are closely spaced and extend substantially side-by-side in a depth dimension of the support body, wherein the block support body comprises a first digit support surface with first and second cuff apertures spaced apart in a sagittal direction, the first cuff aperture aligned with and merging into the first cuff channel and the second cuff aperture aligned with and merging into the second cuff channel, the digit support surface being concave relative to the block body, wherein, in position, the block support body contacts a target digit with the depth dimension being substantially orthogonal to both sagittal and axial directions of the target digit, and wherein the block support body digit contact surface is sized and configured to hold at least a major portion of a width of a target digit thereagainst; a planar non-inflatable elastomeric cuff having a length with opposing end portions, wherein the cuff is slidably insertable through the first and second apertures into the respective first and second channels of the support body so as to extend substantially vertically through the first channel away from the first surface and substantially vertically in a single direction through the second channel away from the first surface to provide the cuff with two substantially vertically extending portions and an intermediate curvilinear portion that extends outward from the support body first surface to receive a digit through the curvilinear portion; and a rod extending laterally across a portion of the cuff, wherein the block support body first channel comprises at least one blocking member extending laterally across at least a portion thereof and a pair of laterally spaced apart first and second cuff retaining shoulders that face each other and reside proximate to but below or above the at least one blocking member, wherein, in use, the rod is first held in the first channel by the at least one blocking member at a first position or orientation under the upper surface of the block body until a defined force associated with a safe occlusive pressure of between about 225 mm Hg and 375 mm Hg is exerted on the digit, then the at least one blocking member yields, separates or breaks to allow the rod to automatically translate to a second position or orientation under the upper surface of the block body and the blocking member generates an audible sound and/or tactile feedback to a user in response to the blocking member action and/or movement of the rod to the second position that indicates that a safe tourniquet pressure has been reached to thereby inhibit an unsafe occlusive pressure, and wherein the second channel includes a pivoting clamp with a user-accessible lever, the clamp attached to the support body proximate the opposing outer surface of the block body, the lever configured to allow a user to pivot the clamp to close against an inner surface of the second channel to contact the cuff and trap the cuff between the clamp and the inner surface of the second channel and pivot the clamp in a reverse direction to release the cuff.
 10. The digit tourniquet of claim 9, wherein the at least one blocking member comprises a deformable projection arm that extends across a minor portion of one side of the first channel, and wherein the rod is held in the channel at an angle against the deformable projection arm and one of the first or second cuff retaining shoulders until the defined force is reached and the deformable projection arm yields to allow the one end portion of the rod to translate a further distance into the first channel to reside against the second cuff retaining shoulder.
 11. The digit tourniquet of claim 9, wherein the at least one blocking member comprises a pair of aligned spaced apart projections that cooperate to hold the rod at the first position in the first channel, then when the defined tension is reached, the rod pushes the spaced apart projects further apart to move down or up to reside against the retaining shoulders.
 12. The digit tourniquet of claim 9, wherein centerlines of the first and second channels and corresponding apertures reside between about 1-20 mm apart, and wherein the cuff has a width of between about 8-15 mm.
 13. The digit tourniquet of claim 9, wherein the concave surface comprises a shallow concave profile with a depth of less than about 5 mm with a medial closed outer surface portion that separates the first and second cuff apertures and channels.
 14. The digit tourniquet of claim 9, wherein the tourniquet is held in a sterile package for surgical use.
 15. A method of applying safe occlusion pressure to a digit during a surgical procedure, comprising: providing a block support body having a digit contact surface and an opposing outer surface, the digit contact surface configured to span at least a major portion of a width of a target digit, the block body also having first and second substantially parallel spaced apart cuff channels extending substantially vertically therethrough and a cooperating substantially planar non-inflatable elastomeric non-inflatable cuff that extends through the first and second channels and out of apertures in the digit contact surface to define an outwardly extending loop, the cuff having a length with opposing first and second end portions with the first end portion attached to a laterally extending rod; placing a digit of interest on the digit contact surface of the support body inside the loop of the cuff; holding the rod and first end portion of the cuff at a first location in the first channel so that the rod engages a blocking member; pulling the second end portion of the elastomeric cuff to tighten the cuff snugly about at least a major portion of the digit to force the digit against the support body; forcing the rod to travel past the at least one blocking member in the first channel in response to the pulling step when a safe occlusive pressure is reached; pivoting a clamp against a portion of the cuff in the second channel to clamp the cuff against an inner surface of the second cuff channel proximate the opposing outer surface of the block body to hold the safe occlusion pressure against arteries in the digit of interest; and automatically providing tactile and/or audible feedback to a user in response to the forcing step when the desired safe occlusion pressure is achieved.
 16. A single-use disposable medical digital tourniquet, comprising: a substantially rigid block support body defining a curved digit contact outer surface and an opposing outer surface, the curved digit contact surface being concave relative to the block body, wherein the digit contact surface having first and second channel apertures, the digit contact surface being sized and configured to hold a target digit thereagainst; and a non-inflatable planar elastic cuff; wherein the support body and digit contact surface span at least a major portion of a width of a target digit, the support body comprising first and second spaced apart cuff channels sized and configured to receive a cuff therethrough, wherein the first and second cuff channels extend substantially side-by-side in a depth direction of the support body between the digit contact surface and the opposing outer surface such that, in position, the cuff extends out of the first and second channels of the block body from the first and second channel apertures in the digit contact surface, wherein the block body and cuff cooperate to provide safe occlusive pressures to both sides of the target digit, wherein, in position, the depth direction is substantially orthogonal to both sagittal and axial directions of a target digit held against the digit contact surface of the support body.
 17. A digital tourniquet according to claim 16, wherein the first and second cuff channels and corresponding first and second channel apertures are closely spaced in a width dimension corresponding to the sagittal direction with axially extending centerlines of the first and second cuff channels residing between about 1-20 mm apart in the width dimension of the support body and with the channels extending a distance in the axial direction to receive a cuff having a width of between about 8-15 mm, wherein the curved digit contact surface has a substantially concave shallow profile, and wherein the cuff extends in a single direction through at least one of the first and second cuff channels such that only one end of the cuff resides below the opposing outer surface of the block body away from the digit contact surface whereby the cuff and the block body cooperate to apply the safe occlusive pressure to arteries in opposing sides of a target digit.
 18. A digital tourniquet according to claim 16, wherein the first and second cuff channels extend substantially parallel for at least a major length of the channels, the support body further comprising an anchoring member configured to hold a first end portion of a cuff in the support body first channel and a pivoting clamping member configured to pivot laterally between open and closed positions and to allow a user to manually pivot the clamping member to clamp the cuff against an inner wall of the second channel at a location that is away from the digit support surface proximate the opposing outer surface of the block body, wherein, in operation, the anchoring and clamping members cooperate with the support body to provide the cuff with a nearly closed loop figure at a desired tension over a target digit held on the support body. 